Technical Field
The present disclosure relates to a heat exchanger, and more particularly to a waste heat exchanger.
Description of the Related Art
Generally, an exhaust pipe waste heat exchanger comprises a cuboid, the inside of which is provided with a plurality of parallel fins. The fins are provided with a hemisphere recess to increase a contact area. Waste heat gas through the fins transmits the waste heat to the surface of the outer tube by serial flow type from the inlet to outlet. The waste heat gas flows downstream with the airflow. The temperature is gradually decreased on the surface of the outer tube. The temperature difference between the upstream side and the downstream side is too large when disposed thermoelectric modules are mounted. The temperature difference may achieve 100° C. on the surface of the outer tube of the exhaust pipe waste heat exchanger.